package vector;

public class vector {
    private int _capacity;
    private int _size;
    private int _Array[];
    private int ERROR = -2147483648;


    public vector () { //default constructor
        _capacity = 10;
        _size = 0;
        _Array = new int[_capacity];
    }
    public vector (int size, int value) { //fill constructor
        if (size > 0) {
            _capacity = 2*size;
            _size = size;
        }
        else {
            _size = 0;
            _capacity = 1;
        }
        _Array = new int[_capacity];
        for (int i = 0; i < _size; ++i)
            _Array[i] = value;
    }

    public int size () {
        return _size;
    }

    public int capacity () {
        return _capacity;
    }

    public boolean empty () {
        return (_size == 0);
    }

    public void reserve (int capacity) {
        if (capacity <= 0)
            return;

        int Temp_array[] = new int[capacity];
        for (int i = 0; i < _size; ++i) {
            Temp_array[i] = _Array[i];
        }
        _Array = Temp_array;
        _capacity = capacity;
    }

    public void resize (int size, int value) {
        if (size < _size && size >= 0) { // zmieniac _capacity?
            _size = size;
            return;
        }

        if (size > _size) {
            if (size >= _capacity) {
                if (2*_capacity > size)
                    reserve (2*_capacity);
                else
                    reserve (size);
            }

            for (int i = _size; i < size; ++i)
                _Array[i] = value;

            _size = size;
        }
    }

    public void push_back (int value) {
        resize (_size + 1, value);
    }


    public void shrink_to_fit () {
        if (_size != _capacity) {
            int Temp_array[] = new int[_size];
            for (int i = 0; i < _size; ++i) {
                Temp_array[i] = _Array[i];
            }
            _Array = Temp_array;
            _capacity = _size;
        }
    }

    public int pop_back () {
        if (!empty())
            return _Array[--_size];

        return ERROR;
    }

    public void print () {
        for (int i = 0; i < _size; ++i) {
            System.out.println(_Array[i] + " ");
        }
    }

    public void clear () {
        _capacity = 10;
        _size = 0;
        int Temp_array[] = new int[10];
        _Array = Temp_array;
    }

    //  public int & at (int id) { // ?
    //      return _Array[id];
    //  }
    //
    //  public int & front () { // ?
    //      return _Array[0];
    //  }
    //
    //  public int & back () { // ?
    //      return _Array[_size];
    //  }

}